Automatic control for keeping predetermined weight on a drilling bit



March 2, 1954 J. w. DES CHAMPS AUTOMATIC CONTROL FOR KEEPINGPREDETERMINED WEIGHT ON A DRILLING BIT 3 Sheets-Sheet 1 Filed Nov. 3,1951 I INVENTOR. fi/vis /4 flew/249m: BY

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AUTOMATIC CONTROL FUR KEEPING PREDETERMINED WEIGHT ON A DRILLING BITFiled Nov. 3, 1951 3 Sheets-Sheet 2 IN V EN TOR. Ty/15'; Mia's [yaw/=5Ma 1954 J w. DES CHAMPS AUTOMATIC CON' IROL FOR KEEPING PREDETERMINEIDWEIGHT ON A DRILLING BIT Filed NOV. 5, 1951 3 Sheets-Sheet 5 IN VEN TOR.

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Patented Mar. 2, 1954 I AUTOMATIC CONTROL FOR KEEPING PRE DETERMINEDWEIGHT ON A DRILLING BIT James W. Des Champs, Buenos Aires, ArgentinaApplication November 3, 1951, Serial No. 254,735

7 Claims. (01. 254 17s) The invention herein disclosed relates to welldrilling operations and particularly to the drilling of deep oil wellswhere there is the need for keeping as nearly as possible, apredetermined weight on the drill to maintain the most effectivedrilling conditions.

The general practice has been for the driller to observe a weightindicator on the deadline and to release the brakes on the spooling drumso as to lower the bit at a rate showing approximately the same load onthe weight indicator. As the driller cannot watch this indicatorconstantly or coordinate his control actions accordingly, such methodsare at best poor approximations of the control desired.

Accordingly, it is a purpose of the present invention to provide anautomatic form of control which will constantly measure the load andimmediately make the necessary corrections to maintain a predetermineddesired Weight on the drill.

It is a further purpose of the invention to provide this automaticcontrol in a simple, substantial form suited to oil field operations,consisting of few sturdy parts which will not get out of order under oilfield operating conditions, which may be readily and easily mounted onand be connected with the drilling rig, which can be furnished atreasonable cost and which as a whole will be entirely practical anddesirable for the purposes indicated.

Other objects and the novel features through which the purposes of theinvention are attained are set forth or will appear in the course of thefollowing specification.

The drawings accompanying and forming part of the specificationillustrate certain present embodiments of the invention but it will beappreciated that structure and operation may be modified and changed asregards the immediate disclosure, all within the true intent and broadscope of the invention as hereinafter defined and claimed.

Fig. 1 in the drawings is an illustration of a rotary rig having theinvention applied thereto;

Fig. 2 is a broken, part sectional and diagrammatic view showing thebalance beam and appurtenant parts removed from the casing of thecontrol instrument; 1

Fig. 3 is a diagrammatic View of the opposed motor control mechanism forthe drawworks;

Fig. 4 is a diagrammatic view of a multiple leverage system for thebalance beam;

Fig. 5 is a broken diagrammatic view of a 2 modification in whichcontrol is exercised by spooling the deadline on a separate winch.

In the general view, Fig. '1, there is shown a rotary rig ofconventional design involving derrick I, draw works 8, rotary 9 anddrill string l0 and bit ll suspended by traveling block l2 from crownblock l3.

The automatic control mechanism is located at l4 on the floor of thederrick, connected wit and actuated by the deadline I5.

Fig. 2 shows how the deadline I5 is run down under and around guidesheaves I6, IT, to a clevis l8 swiveled at I!) to a beam 20 at one sideof the supporting fulcrum 2|.

A weight 22 calculated to balance the deadline load is shiftable alongthe beam at the opposite side of the fulcrum by means of a screw shaft23 which can be turned as by means of a hand crank 24 accessible at theend of the beam or by a reversible motor 25 mounted over the fulcrumportion of the beams A weight applying counter-balance 26 is shownslidably adjustable over the beam at the load applying side of thefulcrum, and this adjustable counter-weight is shown associated with 'a'scale 21 which may be calibrated in terms of tons loading on the bit.

The rocking movements of the beam occasioned by variations in the pullof the deadline caused by the changing penetrating effect of the bit,may be utilized to effect mechanical, electrical, hydraulic, compressedair, or other controls.

In the example shown in Fig. 1, an electric contact 28 on the top of thebeam will engage stationary contact 29 on a bumper 30 to close onecircuit on the lifting'movement, and similar contacts 3|, 32, be closedon the lowering movement of the beam.

The two circuits thus closed and opened may be utilized to efiectreverse movements of the balancing motor 25 which will shift the weight22 to restore balance on the beam after efiecting a change in feedor,'as indicated'i'n Fig. 3, to energize one'of two reversely actingmotors 33, 34, connected with a worm'35 in engagement with worm gear 36on the spooling drum or other shaft 31 of the draw works.

Other electrical control devices may be actuated from the switches orswitch contacts directly or indirectly actuated by'the beam.' In someinstances only one of these'switches may be used and such switch'o'r'switches maybe associated with other control equipment such as aDynamatic brake or hydraulic or air actuated control equipment. 7

In Fig. 2 the end of the beam is shown as carrying an extension 38 foractuating the toggle 39 of an air controller 40 for draw works brakes orthe like.

Fig. 4 shows how the beam may be actuated through a leverage system inthe form of a lever 4| connected with the deadline at one end, fulcrumedat 42 and bearing at 43 at the opposite end on a secondary lever 44pivoted at one end at 45 and connected at the opposite end through apull link 46 with the beam at the loading side of the beam fulcrum 2|.

Necessary control connections will vary according to the particularcontrol system employed.

Fig. 2 shows how with main switch 41 closed, circuit will be completedthroughconnections 48, 49, to energize the reversible balancing motor inone direction when the beam closes the upper switch contacts 28, 29, andcircuit be completed through connections 59, 49, to energiz this motorin the reverse direction when the beam closes circuit through the lowerset of contacts 3!, 32.

In Fig. 3 a circuit arrangement is shown for controlling two motors 33,34, directly or indirectly geared to the spooling drum for paying out ortaking in cable as the need for adding or subtracting weight on the bitarises, as indicated by lifting or lowering movements of the beam end.

The upper switch contacts 28, 29, are here shown connected by wiring 5|and 52 with motor 33 and main switch 53, this switch and the motorconnected with the supply circuit at 54, 55.

The lower control switch 3 l, 32, is shown connected by wiring 58, 51,with motor 34 and the double pole main switch 53, with connectionscompleted'through wiring58 and 59 to opposite sides of the-line.

Mechanical, hydraulic, air or other operating connections maybeemployed, th air valve indicated at 40, Fig. 2, operated by the end ofthe beam constituting one example of the same.

The main switch such as 41 in Fig. 2, or 53 in V Fig. 3, permits theautomatic control to be shut off until drilling operations commence.Then on-the closing of this switch the beam may be balanced against thepull of the deadline by shifting the balance weight 22 by hand at 24 orthrough motor 25. After the load of the drill string and bit is balancedthe counter-weight 25 may be shifted toward the deadline pull connectionHi to in efiect lighten the pull on the beam and apply control foradding weight to the bit; in other words, effect a lowering of the bitin the hole. By proper calibrations this loading effect may b indicatedby the counter-weight scale 21, or other means may be employed forindicating actual weight on the bit.

This loading or weighting of the bit may be accomplishedalso'by'shifting the balance weight 22 on the beam'and employing thebalancing motor 25 to automatically shift the balancing weight as theneed arises to apply less or more weight to the drill.

As another or different method of balancing the beam, the fulcrum forthe beam may be made shiftable as by locating it on a block 50, Fig. 2,slidable in a slot orguideway 6| in the beam. This block-may carry anindex or scale registrable with a-scale or index on the beam to showvariations-in leverage ratios, weight or other values, to-aid thedriller-in effecting desired fulcrum settings. These fulcrumadjustmentsmay be effected by screw or other forms of gearing providingthe necessary leverage and power for accomplishing relative shifting ofthe fulcrum center. The trunnion mounting for the fulcrum is not shownbut it will be appreciated that this is structurally capable of carryingthe full loads that may be imposed on the beam.

The invention provides simple and effective means for automaticallyadding or subtracting weight on the bit directly and immediately as theneed for such adjustments is sensed by the deadline. The equipmentnecessary for th purpose may be compact and small enough to be locatedon the derrick floor or other convenient, appropriate place, out of theway of other drilling equipment and operations.

Fig. 5 shows how the purposes of the invention maybe attained byspooling the end of the deadline IS on a separate drum 62 which may becontrolled from the beam 20 and be driven one way .or the other byreversible motors or the like, in the same manner as disclosed in Fig.3,

This construction has the advantage that the invention may be installedwithout making any changes in the draw works.

In this construction the loaded end of the supplementary bar 4| carriesa sheave 63 over which th deadline is run to the drum. The controlmechanism for the winch in both Figs. 4 and 5 may be like that shown inFigs. 1, 2 and 3. In all cases the deadline is directly or indirectlyconnected with the balancing beam, and the drum control mechanism isoperated by this beam in accordance with actual load on the beam.

What is claimed is:

1. Automatic control apparatus for maintaining desired weight on thebitof a rotary drill having cable supporting the drill string andterminating in a deadline, and comprising a beam fulcrumed for balancingmovement and equipped with means for effecting connection of thedeadline therewith and whereby said beam will be subject to the pull ofsaid deadline, means for balancing the-beam against the load of thedrill string supported by the cabl and asserted by pull of the deadlineon the beam, a counterweight adjustable on the beam to the effect ofapplying weight to the drill string and control mechanism operable bythe beam for effecting weight loading or unloading of the drill stringin accordance with the movements of said beam.

2. Automatic control apparatus for maintaining desired weight on the bitof a rotary drill having cable supporting the drill string andterminating in a deadline, and comprising a beam fulcrumed for balancingmovements and equipped with means for effecting connection of thedeadline therewith and whereby said beam will be subject to th pull ofsaid deadline, means for balancing the beam against the load of thedrill string supported by the cable and asserted by pull of the deadlineon thebeam, a counterweight adjustable on the beam to th effect ofapplying weight to the drill string, control mechanism operable by thebeam for effecting weight loading or unloading of th drill string inaccordance withthe movements of said beam and a variable fulcrum for thebeam shiftable relative to the beam for effecting initial leverageratios as between the fulcrum and deadline connection centers of thebeam.

3. Automatic control apparatus for maintaining desired weight, on thebit of a rotary drill having. cablesupportingthe drill string andterminating in a deadline, and comprising a beam fulcrumed for balancingmovements and equipped with means for effecting connection of thedeadline therewith and whereby said beam will be subject to the pull ofsaid deadline, means for balancing the beam against the load of thedrill string supported by the cable and asserted by pul1 of the deadlineon the beam, a counterweight adjustable on the beam to the effect ofapplying weight to the drill string, control mechanism operable by thebeam for effecting weight loading or unloading of the drill string inaccordance with the movements of said beam and motor driven mechanism onthe beam for shifting said balance weight.

4. Automatic control apparatus for maintaining desired Weight on the bitof a rotary drill having cable supporting the drill string andterminating in a deadline, and comprising a beam fulcrumed for balancingmovements and equipped with means for eiiecting connection of thedeadline therewith and whereby said beam will be subject to the pull ofsaid deadline, means for balancing the beam against the load of thedrill string supported by the cable and asserted by pull of the deadlineon the beam, a counter weight adjustable on the beam to the effect ofapplying Weight to the drill string, control mechanism operable by thebeam for efiecting weight loading or unloading of the drill string inacoordance with the movements of said beam and motor driven mechanism onthe beam for shifting said balance weight and said control mechanismincluding connections for eifeoting operation of said balance motor.

5. Automatic control apparatus for maintaining desired weight on the bitof a rotary drill having cable supporting the drill string andterminating in a deadline, and comprising a beam fulcrumed for balancingmovements and equipped with means for effecting connection of thedeadline therewith and whereby said beam will be subject to the pull ofsaid deadline, means for balancing the beam against the load of thedrill string supported by the cable and asserted by pull of the deadlineon the beam, a counterweight adjustable on the beam to the effect ofapplying weight to the drill string and control mechanism operable bythe beam for effecting weight loading or unloading of the drill stringin accordance with the movements of said beam and including valvemechanism having a controller shiftable by said beam.

6. Automatic control apparatus for maintaining desired weight on the bitof a rotary drill having cable supporting the drill string andterminating in a deadline, and comprising a beam fulcrumed for balancingmovements and equipped with means for efiecting connection of thedeadline therewith and whereby said beam will be subject to the pull ofsaid deadline, means for balancing the beam against the load of thedrill string supported by the cable and asserted by pull of the deadlineon the beam, a counter-weight adjustable on the beam to the efiect ofapplying weight to or subtracting it from the drill string and controlmechanism operable by the beam for effecting weight loading or unloadingof the drill string in accordance with the movements of said beam, and awinch controllable for winding in or paying out said deadline, said beamhaving a sheave over which said deadline passes in its run to saidwinch.

7. Automatic weight control mechanism for a rotary drilling rig havingdraw works for spooling the hoisting cable supporting the drill stringand bit and with the cable terminating in a deadline, means forcontrolling the draw works for applying Weight or taking weight off thebit, a beam fulcrumed for balancing movements and having means foreffecting connection of the deadline thereto at one side of the beamfulcrum and means operated by said beam for effecting actuation of saiddraw works controlling means, and a separately controlled winch forspooling the end of said deadline, said beam having a sheaveconstituting the means for efiecting connection of the deadline and overwhich the deadline is looped on its way to said separately controlledwinch.

JAMES W. DES CHAMPS.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,294,089 Graham Feb. 11, 1919 1,779,581 Behnke Oct. 28, 19302,068,565 OKey Jan. 19, 1937 2,073,445 De Iongh Mar. 9, 1937 2,348,382I-Ialby May 9, 1944

